Gas Sensor Detecting 3-Hydroxy-2-butanone Biomarkers: Boosted Response via Decorating Pd Nanoparticles onto the {010} Facets of BiVO Decahedrons.

The newly emerged gas sensing detection of 3-hydroxy-2-butanone (3H-2B) biomarker is deemed as an effective avenue to indirectly monitor (LM). However, 3H-2B sensing materials requiring critically high sensitivity and selectivity, and ppb-level detection limit, remain challenging. Here, we report the advanced gas sensors built with bismuth vanadate microdecahedron (BiVO MDCD) {010} facets selectively decorated with Pd nanoparticles (Pd NPs, Pd-{010}BiVO MDCDs) for boosted detection of the 3H-2B biomarker. Meanwhile, BiVO MDCDs with overall facets are randomly deposited with Pd NPs (Pd-BiVO MDCDs). Comparatively, Pd-{010}BiVO MDCD sensors show 1 order of magnitude higher response toward the 3H-2B biomarker at 200 °C. Further, Pd-{010}BiVO MDCD sensors enable to detect as low as 0.2 ppm 3H-2B and show best selectivity and stability, and fastest response and recovery. Density functional theory calculations reveal a lower adsorption energy of 3H-2B onto Pd-{010}BiVO MDCDs than those of pristine and Pd-BiVO MDCDs. The extraordinary Pd-{010}BiVO sensing performance is ascribed to the Pd NP-assisted synergetic effect of the preferential adsorption of 3H-2B target molecules, accumulated sensing agent of ionic oxygen species, and concentrated catalysts on the {010} facets. This strategy offers rapid and noninvasive detection of LMs and is thus of great potential in the upcoming Internet of Things.